1. Field of the Invention
The present invention relates to a laminated ceramic electronic component, and in particular, to a laminated ceramic electronic component such as a laminated inductor, a laminated impedance component, a laminated transformer, and a high frequency line device, and a method for producing the same.
2. Description of the Related Art
In general, a laminated ceramic electronic component such as a laminated inductor is produced as follows. Firstly, a mother ceramic laminated block including a plurality of ceramic laminated products is formed. The mother ceramic laminated block is cut according to the arrangement of inner conductors, such as conductors for a coil and lead conductors, to provide each ceramic laminated product. The resultant ceramic laminated product is fired. Subsequently, outer electrodes are formed on the surface of the ceramic laminated product to provide a final product.
When the inner conductors and the lead conductors are formed by normal screen printing, the conductors have a thickness of about 20 μm. With such a thickness, when the mother ceramic laminated block is cut, mechanical stress applied to the lead conductors is small. Therefore, defects such as cracking are typically not generated.
Japanese Unexamined Patent Application Publication No. 2002-305123 discloses a method for producing a conductor for a coil. According to this method, a conductor layer for a coil integrated with a lead portion is transferred a plurality of times so as to overlap each other. Thus, a conductor for a coil having a conductor thickness after the firing of, for example, about 70 μm to about 80 μm is produced.
However, with such a large thickness of the conductor, when the mother ceramic laminated block is cut, excessive mechanical stress is applied to the lead portion of the conductor for a coil. As a result, defects such as cracking are often generated.
Further, it is known that ferrite has the magnetostrictive effect in which the permeability is changed depending on the stress. The production of a laminated ceramic electronic component has the following problem. When laminated green sheets including ferrite and inner conductors are fired, stress caused by the difference in the shrinking characteristics is applied to the ferrite. Consequently, the permeability of the ferrite is decreased.